Engine failure

[Yealm]

Engine stopped suddenly yesterday with alarm going off and smoke and fumes. Chucked the anchor over and waited to be rescued.
Found the exhaust had ruptured!
Beta 25, fitted new about 3 years old.
Was wondering if this is a factory part or something modified to fit the boat? And why it should go?

(sorry upside down images!)

 

[Tranona]

That is the highrise manifold and by the looks of it has been cut and welded because it was too "high" to fit under the cockpit sole (probably).

 

[doug748]

Mine went in a similar place after about 15 years which I thought was about par for the part. There was evidence of internal corrosion

I agree, it looks as if two cuts have been made in the bend and re-welded but that may not explain the failure. The exhaust hose is rigid stuff and if one end, of a short run, is held rigid it may well stress the failed area. I loosened the mountings of my water trap to help in this respect.

After such a short time I am sure Beta will give a good deal on a replacement - should be c£200 or less. It might just be worth speaking to Phoenix 316 in Plymouth to get a price for having one made up.

Will post a photo of my old one when I find it.

.

 

[doug748]

Here it is, original fitting from a c2008 20hp. I may have it refurbished and keep as a spare, not a huge job.

 

[Yealm]

Many thanks! It’s being re-welded today. Will replace it over the Winter.

Wondering if the main issue is a botched weld or due to some vibration/shaking ?

 

[oldharry]

If its lying in its 'natural' position in Pic 2, then it's under stress. That with a possibly weak weld, and vibration is a possible cause of the failure

 

[capnsensible]

I think exhausts on yachts (various) have given me more problems than any other kind of defect.

Hope your repair works OK.

 

[Sail Away]

Snap!

Beta 25 exhaust elbow, engine new in 2017, 700 running hours.

Picked a particularly bad moment to fail, while trying to berth in small marina in strong winds, lots of revs needed. Once berthed, found engine bay and bilge completely flooded. Took a full day to cleanup, not good!

After the event, did notice some staining under the lagging fitted around the elbow, so it had been failing for some time. Had the elbow re-welded and this time didn't take the lagging over the joint that failed. Hopefully easier to spot a problem in the future.

Have now heard of a few similar problems with Beta high-rise exhaust elbows. The failed weld is subject to high thermal stresses, as it is just above the water injection point, so a large temperature difference across the weld. So thermal cycling and internal corrosion due the exhaust fumes, eventually resulting in failure. I think I may get the elbow re-built with the weld moved further away from the water injection sleeve. This should reduce the thermal stress in the weld.

Lesson learned, checked the exhaust elbow regularly!

 

[Slowboat35]

Looks like a seriously carp quality weld to me, especially the part 9 o'clock to 1 o'clock.

 

[Yealm]

Very interesting!
I wonder how useful checking is- whether likely to be visible signs prior to rupture?

 

[DownWest]

While the OPs was modded to fit, that is not where it failed. A call to Beta would be in order... Frequent inspections would probably show the crack starting, but you would have to look closely.

 

[mjcoon]

While the OPs was modded to fit, that is not where it failed. A call to Beta would be in order... Frequent inspections would probably show the crack starting, but you would have to look closely.

I think serious crack engineering uses a UV dye which runs along the crack and makes it visible under UV lighting. en.wikipedia.org/wiki/Blacklight

 

[doug748]

Very interesting!
I wonder how useful checking is- whether likely to be visible signs prior to rupture?

Mine did not fail I found it cracked when I took it off for a de-coke check. Mind you it was shot, I opened the crack by hand and it fell apart. I don't think it would have lasted more than a few hours, I was just lucky.

.

 

[Yealm]

Mine did not fail I found it cracked when I took it off for a de-coke check. Mind you it was shot, I opened the crack by hand and it fell apart. I don't think it would have lasted more than a few hours, I was just lucky.

.

Gosh, that's 3 of us !
Inherent vulnerability of exhausts in general, or a specific design/manufacturing defect?

 

[DownWest]

I think serious crack engineering uses a UV dye which runs along the crack and makes it visible under UV lighting. en.wikipedia.org/wiki/Blacklight

The easy version uses dye and a powder spray. Apply the dye, wipe off, then spray the powder. The powder pulls the dye out of the crack and shows as a broad line.

 

[capnsensible]

When delivering yachts, the engine exhaust is always something I give as best a looking at as I can. Including a good old shake. Not perfect by any means, but at the very least one gets familiar with the pipe run and access.

On my own yacht I carried plenty of JB Weld and decent size jubilee clips. A patch cut out of a food tin plus those items got me out of bother once.

 

[LadyInBed]

The last pic in Sail Away's #8 post looks in serious need of a collar welded over the joint to support the crap weld!

 

[Sail Away]

Very interesting!
I wonder how useful checking is- whether likely to be visible signs prior to rupture?

Welds rarely fail suddenly, much more likely to be a progressive failure over time. In my case, the brown staining you can see around the failed joint was a warning sign. Unfortunately the lagging I had wrapped over that area obscured this. Did not look close enough. Friend with a Beta 43 and same high rise elbow spotted a pinhole crack in the weld, luckily well before complete failure. Again only a few years old.

So I would say yes, regular careful inspection should pick up a problem. Using dye penetrant crack detector spray would be even better.

Also agree with other posters, weld penetration is not good and this won't have helped.

 

[Adios]

Chucked the anchor over and waited to be rescued.

Just curious but from where and how did you get back in?

 

[oldmanofthehills]

I love my newish Beta 25 with its high rise exhaust. However I will be checking its fidelity in future to guard against unexpected partings!

Has anyone contacted Beta about this matter as failure after so few years suggests some kind of manufacturing deficiency